Horizontal wet-dry pressure chamber



Dec. 22, 1970 LANPHlER. ETAL 3,548,516

HORIZONTAL WET-DRY PRESSURE CHAMBER Filed Dec. 23, 1968 N VEN TOR? 68% United States Patent 3,548,516 HORIZONTAL WET-DRY PRESSURE CHAMBER Edward H. Lanphier, Eggertsville, and Richard A. Morin, Snyder, N.Y., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Dec. 23, 1968, Ser. No. 786,166 Int. Cl. B63c 11/02 US. CI. 35-29 14 Claims ABSTRACT OF THE DISCLOSURE The disclosure concerns a means and method for accommodating experiments on personnel or equipment at very high pressures in a water environment wherein a water volume is maintained at one end of a pressure chamber and an air volume is maintained horizontally adjoining the water volume in the same chamber. No structure is introduced or necessary to divide the two volumes, an air-water interface being maintained in a horizontal plane by pressure conditions in the air volume of the chamber.

The invention described herein may be manufactured and used by or for the Government of the United States of Americafor governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to high pressure chambers and, in particular, to a high pressure chamber having horizontally adjoining air and water volumes.

In physiological experimentation and research, it is desirable that horizontally disposed areas be available primarily so that normal horizontal movement of persons undergoing tests may be accommodated and observed. The present devices for accommodating human experiments of this and other nature under very high pressure conditions have been restricted to vertically disposed chambers only, the depth simulation in such chambers being achieved by pressurization of the air above the fluid to that pressure which represents the desired depth. Though such vertical chambers could be adapted to accommodate horizontal as well as vertical movement of personnel and equipment, their cost would be prohibitive among other disadvantages. Vertical chambers additionally are undesirable because their longitudinal dimension is so large as to introduce a wide variation in pressure between the upper and lower portions thereof.

It has, therefore, long been desired that a horizontally disposed, compact chamber be available at reasonable cost so that physiological experimentation in, e.g., deep diving may be performed. A horizontal chamber of this nature would be further desirable if an air space were pro vided adjacent the water space with free passage between the two spaces afforded without the necessity of access doors, watertight hatches, etc. Such a horizontal chamber would not only permit simulation of horizontal movement at correct depths, but also would provide a rest and rescue area at the same pressure as the water environment and within easy access thereto so that a person under experimentation could quickly move or be moved to the air volume for rest, readjustment, etc.

The present invention avoids the disadvantages of vertical chambers and provides a horizontal combination of spaces in a single chamber whereby an air-water interface may be positioned at any desired point along the longitudinal axis of the chamber so that a desired ratio of horizontal length of water volume as Well as air may be set up. The chamber preferably is cylindrical along the longitudinal axis and hemispherical at the ends. The length of the chamber therefore may be any desirable distance commensurate with the amount of horizontal water vol- 3,548,516 Patented Dec. 22, 1970 ume desired. The remainder of the chamber may be devoted either to a pressurized air volume or may contain both a pressurized air volume and an adjacent entrance lock which also could serve as a decompression chamber. The invention operates on the principle of water being held in place by atmospheric pressure. In one embodiment, the air and water volumes are separated by a pair of barriers in the form of partial bulkheads which overla near the center line of the cylinder and which are spaced apart a sutficient distance to accommodate passage of a human being or an object to be tested.

Accordingly, it is an object of the present invention to provide a chamber for submerged studies which combines an air volume and a water volume without the normal accessories and adjuncts required in separate airand water-compartmented chambers.

Another object of the present invention is to provide a chamber for submerged studies wherein the water volume is horizontally disposed so as to facilitate primarily studies of horizontal movement under selected pressure conditions.

A further object of the invention is to provide a chamber for submerged studies wherein the water volume is horizontally disposed and adjoins an air volume also horizontally disposed so as to permit ingress and egress between the two volumes without the impediments associated with compartmented structures.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description thereof when considered in conjunction with the accompanying drawings in which like numerals represent like parts throughout and wherein:

FIG. 1 is a schematic drawing of one embodiment of the invention wherein the water and air volumes are combined in a single chamber with an entrance lock;

FIG. 2 is a sectional view of another embodiment of the invention wherein the entrance lock is in a separate chamber which is joined to the air-water chamber; and

FIG. 3 is a front elevation with parts broken away and shown in section of the embodiment shown in FIG. 2.

Referring to FIG. 1, a chamber 11 is shown formed of a central cylindrical section 12 and hemispherical end sections 13 and 14. The interior of chamber 11 is divided into three volumes, a water volume 17, an air volume 18 and an entrance lock 19. Water volume 17 and air volume 18 are formed by a pair of partial bulkheads 22 and 23 which may be afiixed to the wall of chamber 12 by conventional means such as welding or which may be movably positioned so that the ratio of space between volumes 17 and 18 may be varied to suit experimental needs. Partial bulkhead 22 provides the barrier for confining the upper volume of water in space 17 and extends downward to a point substantially below the upper edge of partial barrier 23. The partial barriers are spaced apart a selected distance sufiicient to accommodate the passage of either personnel or equipment or both between the two volumes. An air-water interface 25 is established between the partial bulkheads during initial filling and is maintained thereafter by the pressure in volume 18. Air under selected pressure is admitted into volume 18 through line 26 which is controlled by valve 27, while water is admitted to volume 17 through line 28 which is controlled by valve 29. A vent line 32 and valve 33 provide for venting of air from volume 17 as it is filling with water, and a drain line 34 with control valve 35 provide for draining volume 17. Entrance lock 19 is formed of end section 14 and a bulkhead which include, respectively, access hatches 42 and 43. The pressure in the entrance lock is maintained through an air line 45 controlled by a valve 46. Chamber 11 is shown diagrammatically supported on supports and 51 which need not be permanently afiixed to either the chamber or a base 52 since chamber 11 is not so prohibitive in weight and volume as to necessarily be permanently installed at a single location.

In FIGS. 2 and 3, a two-compartment arrangement is shown wherein chamber 60 is formed of a cylindrical intermediate section 61 and hemispherical end sections 62 and 63 while an entrance lock 64 is affixed to chamber 60 by a watertight connection 65. Water volume 17 and air volume 18 in chamber 60 are maintained as in the embodiment of FIG. 1 by partial bulkheads 22 and 23. Entrance into air volume 18 is provided through a pair of batches 68 and 69 which are attached to connection 65 and may be provided with sealing fittings such as dogs, not shown, or other conventional means for providing a watertight and airtight seal. End 62 of chamber 60 is provided with a viewing port 71 which comprises a collar 72 secured to chamber 60 and a port 73 which is pivotally attached to the collar. Venting and supply lines are provided in a similar manner as in the embodiment of FIG. 1.

The entrance lock 64 has a hatch fitting 75 including 2.

hatch 76 through which ingress and egress are accomplished. In FIG. 3, the overlapping of partial bulkheads 22 and 23 is depicted schematically by line 77 which represents the lower edge of remote bulkhead 22 and line 78 which represents the upper edge of bulkhead 23. A separate support 80* is provided for the entrance lock.

Chambers such as 11 preferably are made of transparent material such as Plexiglas or Teflon so that experiments may be viewed by laboratory personnel outside the chamber. Where the operating pressures are so high as to preclude the use of transparent material, chamber 60 would be used and necesarily would be made of steel or material of equivalent strength. Observation into such a chamber is accomplished through viewing port 71 and partial bulkheads 22 and 23 which in either embodiment may be made of plate glass or Plexiglas since the differential pressure to which these barriers are subjected is relatively small. If it is desired that bulkheads 22 and 23 are to be movable, these bulkheads may be sealed to the chamber wall by any suitable removable elastic seal such as a bicycle inner tube, not shown, inflated with water to avoid compression at elevated chamber pressures. To permit use of such a seal, the adjacent surfaces of the chamber walls must necessarily be made smooth such as by the use of epoxy resin or several coats of epoxy paint. These movable barriers would be placed against pads, not shown, which would be welded to the chamber walls at appropriate intervals.

An alternate arrangement for pressurizing the chamber may include an air pressure unit installed in the upper portion of the air volume, not shown, with pressure release effected through line 26. Under either pressurizing system, chambers 11 and 60 preferably are partially filled at atmospheric pressure to the desired level of air-water interface 25. At this point, pressure in air volume 18 is increased concurrently with the entry of additional water so that the level of the air-water interface remains unchanged. As water fills the water volume, air above the volume is vented through vent 32 until the entire water volume is filled with water. It has been determined that a cylinder six feet in diameter should require pressure of less than three p.s.i. to fill where the air-water interface is substantially at the bottom of the cylinder. With an interface near the cylinder centerline, the maximum pressure difference should be less than 1.5 p.s.i. When the water volume is filled, the pressure at the top is negative with respect to the pressure maintained in the air volume and the pressure at the bottom of the water volume is positive with respect to the pressure in the air volume. That is, the pressure throughout the air volume is identical while the pressure in the water volume varies either positively or negatively with respect to the vertical distance above or below the air-water interface.

The pressures involved are small enough so that partial bulkheads 22 and 23, or other types of barriers, may be constructed of relatively light materials. Sealing between the barriers and the chamber wall is critical particularly at the upper barrier since a significant gas leak into the water volume past the upper barrier would allow the water level to overflow the lower barrier.

Since water is essentially incompressible and transmits pressure freely, increases in the gas pressure in the air volume are communicated to the entire system thereby permitting any desired pressure to be achieved throughout the chamber. Gas is not permitted to accumulate in the wet section so that the problem of expansion or compression of a gas and its effect on the water level is avoided.

In using the invention, personnel and/ or equipment can make immediate preparations for entry into the water volume from a position in the air volume. When ready, personnel and objects may move freely through the interface 25. Bulkheads 22 and 23 extend below and above the interface, respectively, a sufiicient distance to accommodate the volume of the personnel and equipment to be added to the water volume. Air interface 25, therefore, is displaced upward when personnel and objects are added to the water volume so that it is essential that bulkhead 23 especially be of suflicient height to accommodate expected changes in the level of the interface. Steps or other means for assisting the movement of persons and equipment from one side of bulkhead 23 to the other may be added as desired.

The present invention thus provides, among other advantages, a facility which is especially adapted for horizontal movement experiments in pressurized water volumes. It avoids any need for compartmentation to permit persons and objects to be moved freely from a water environment to an air environment and in this respect additionally provides the significant advantage of a much lower cost requirement than that of a vertically disposed chamber having such utility. Where movable barriers are used, the facility becomes increasingly versatile for experimentation since a greater horizontal distance can be made available with no change in cost and with an insignificast amount of effort required to displace the barriers. By removing any necessity for a large fraction of gas volume, the invention greatly reduces the quantity of compressed gas required to reach a given pressure for studies which do not require the entire volume of the compartment. That is, the water volume can be extended in cases where movable barriers are used to substantially occupy the entire chamber so that the air volume to be compressed can be reduced to a bare minimum. Where transparent barriers are used, the submerged personnel and equipment may be observed by tenders in the air volume with a far better view than that afforded through ports or by observing through the usual hatch in conventional wet-pot vertical chambers.

Free passage through interface 25 eliminates the need for hoists, ladders and similar arrangements for accommodating personnel and equipment. Greater safety measures can be observed because of the invention since in the event of an accident such as a malfunction of breathing apparatus the subject can simply move through the interface and into the air volume. A tender may be stationed for as long periods as desired in the air volume and may be provided with an ample emergency breathing apparatus for use in aiding a disabled subject.

The fact that the pressure at the level of interface 25 is equal to the pressure in air volume 18 should greatly facilitate many measurements and tests which may be conducted in the chamber. Without such a pressure condition, elaborate and often unsuccessful attempts to achieve balanced pressure between a submerged subject and measuring apparatus which cannot be submerged is encountered. Also, instruments may be maintained dry in the air volume at the same pressure as the subject thus avoiding a requirement for special arrangements such as housings or access hatches for introducing such instruments into the chamber.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. For example, the bulkheads separating the air and water volumes need not extend transversely from the chamber wall 'but may be positioned at various angles thereto to define various configurations of air and water volumes.

What is claimed is:

1. A high pressure research vessel comprising:

a chamber adapted to be horizontally disposed;

means dividing the chamber into adjoining, partially overlapping horizontal spaces for maintaining separate air and water volumes,

said chamber dividing means forming an airwater interface at the overlap area so that persons and objects may pass freely through the interface from one space to the other; and said chamber including access means at least from the external environment into the air volume, means for varying the air pressure in the air volume and means for filling and venting the water volume,

whereby studies of swimming and other substantially horizontal underwater activities and effects may be conducted under selected pressure conditions with recourse to the air volume without the impediment of hatches or other closures.

2. The high pressure vessel as defined in claim 1 wherein said air-water interface is horizontally disposed at a level which permits ready ingress and egress for both personnel and equipment.

3. The high pressure vessel as defined in claim 2 wherein said chamber dividing means includes at least two substantially vertical barriers, one of which defines the upper portion of the water volume at the interface and the other the lower portion of the water volume at the interface,

said barriers spaced apart a selected distance to accommodate said passage of persons and objects therebetween.

'4. The high pressure vessel as defined in claim 3 wherein said barriers are movable longitudinally with respect to the centerline of said chamber so as to vary as desired the space allocated to air volume and water volume.

5. Apparatus adapted to accommodate horizontally adjoining air and water volumes for laboratory experimentation under selected pressure conditions comprising:

chamber means elongate horizontally to accommodate adjoining interconnected spaces for containing air and water masses;

said spaces defined by one barrier extending downward a selected distance from the top of the chamber and another extending upward a selected distance from the bottom of the chamber so as to confine a volume of water of desired configuration;

said barriers substantially parallel and positioned a selected distance apart so as to accommodate therebetween the free passage of personnel and equipment;

means for admitting water under selected pressure into one of said spaces and air under selected pressure into the other space; and

access means for providing access at least from the external environment into the air volume so that said adjoining spaces may be filled with water and air, respectively, to a pressure determined by the pressure in the air space and passage between said spaces is afforded at all pressures through the air-water interface.

6. The apparatus of claim 5 and further including an entrance lock interposed between the air volume and the environment;

access means in said entrance lock communicating with the environment; and

mtianls for controlling the air pressure in said entrance 7. The apparatus of claim 6 wherein said chamber is cylindrical in the longitudinal dimension and spherical at the ends;

said access means into said air volume being positioned within the cylindrical portion of said chamber.

8. The apparatus of claim 7 wherein the water volume of said chamber is adapted to be partially filled to the desired level of the air-water interface under ambient pressure as the pressure in the air volume is increased.

9. The apparatus of claim 8 wherein said barriers are made of transparent material so that experiments may be viewed from said air space.

10. The apparatus of claim 5 and further including an entrance lock connected to said chamber adjacent the air volume access means,

said entrance lock having external access means communicating with the environment; and

means for controlling the pressure in the entrance lock.

11. The apparatus of claim 10 wherein said barriers are made of transparent material so that experiments may be viewed from said air space.

12. The apparatus of claim 11 and further including a viewing port in the end of said chamber containing water.

13. The method of providing in a pressurized chamber interconnecting horizontally disposed air and water spaces comprising the steps of:

dividing said chamber transversely into staggered interior spaces which overlap at a horizontally disposed interface;

determining the level of said interfacte by defining the larea of overlap of the means for dividing the chamdetermining the passage between said spaces by defining the longitudinal distance between the chamber dividing means in the region of the interface;

filling the water space by first admitting water thereinto at ambient pressure to the level of the interface and thereafter admitting Water under selected pressure concurrently as air under controlled pressure is admitted into the air space;

venting the air trapped above the water as the water space is filled; and

providing controlled access to the environment from the air space.

14. The method of claim 13 and further including the step of simulating the pretssure at selected water depths by varying the pressure in the air space of the chamber.

References Cited UNITED STATES PATENTS 3,368,556 2/1968 Jensen et al. 128--204 FOREIGN PATENTS 782,247 9/1957 Great Britain 616-9X HARLAND S. SKOGQUIST, Primary Examiner US. Cl. XJR- 

